Disclaimer: Always download DirectX redistributables from official Microsoft sources to avoid malware. The offline cache creation method described is a workaround, not an official package, but uses only Microsoft-signed files.
No. Microsoft does not provide a standalone DirectX 12 offline installer because it’s integrated into the OS. The closest is the DirectX Runtime redistributable (which includes up to DX11). Directx 12 Download Windows 10 64 Bit Offline Installer
Q: Can I install DirectX 12 offline? A: Yes, you can install DirectX 12 offline using the offline installer. not an official package